Among Methadone Patients With Psychiatric Conditions, Only Cannabis Use Was Elevated

Among 588 patients receiving opioid agonist treatment with methadone, 63.5% had a lifetime dual diagnosis and 83.5% reported past-month substance use. Having a psychiatric comorbidity was not associated with increased use of opioids, cocaine, or alcohol, but was associated with a 29% increase in cannabis use (PR=1.29).

Cross-sectional study of 588 convenience-sampled patients from eight outpatient drug treatment centers in Catalonia, Spain. Dual diagnosis assessed using the Dual Disorder Screening Interview. Self-reported substance use evaluated via questionnaire. Poisson regression models adjusted for sociodemographic, clinical, and treatment variables.

Understanding why cannabis is the only substance elevated among dual-diagnosis methadone patients could inform treatment. It suggests cannabis may serve a different role than other substances for people managing both opioid use disorder and psychiatric conditions.

The selective association between psychiatric comorbidity and cannabis use (but not other substances) in methadone patients may reflect self-medication patterns. Cannabis might be perceived as less harmful or more accessible than other substances for managing psychiatric symptoms.

Cross-sectional design from one region of Spain. Convenience sample may not represent all methadone patients. Self-reported substance use. Lifetime diagnosis doesn't capture current symptom severity.